This invention is related to the field of latching mechanisms and, more particularly, is related to the field of latching mechanisms which prevent the opening of a cover or guard over a rotatable member, such as a centrifuge rotor, when it is in motion.
An extremely important safety consideration with respect to the operation of the centrifuge is to prevent opening of the cover while the rotor is still in motion, as inadvertent contact with a rotor turning at high speed could have serious consequences. Also, while the cover is open, the operator is exposed to a safety hazard in that the sample holding test tubes in the rotor could break and send fragments out of the centrifuge at high speed.
A practical motion-sensing safety lock for use in a machine having a rotatable member is disclosed by Christopher Morrison Schwab in U.S. Pat. No. 4,076,288, assigned to Beckman Instruments, Inc., the assignee of the present invention. Schwab teaches the use of a control element for sensing the rotation of the rotatable member within a machine to automatically prevent opening of a cover or guard on the machine when the member is rotating. The control element has one of its ends brought into contact with a portion of the rotatable member and its other end connected to a latching mechanism located adjacent the machine cover. The control element, being an elongated flexible member, moves in response to the rotation of the rotatable member. When the rotatable member is stationary, one end of the control element abuts the rotatable member at a point substantially in line with the member's central axis, causing the control element to become an elongated rigid member to permit the latching mechanism to turn and allow the opening of the cover over the rotatable member. When the member is rotating, the contact end of the control element adjacent the member is deflected, causing the other end of the control element connected to the latching mechanism to recede from its rigid position and prevent the movement of the latching mechanism and thereby retain the cover in a locked condition over the rotating member.